Microsoft has released Language Packs for SP 2010. Thank you. Now I can try to upgrade existing Installations :-)
But wait. The Languages Packs won’t install on my Windows 7. It says they need a Windows Server 2008 x64. Right. But it’s the same with the Server itself. We have to modify the config file, to support an installation on a non Server OS.
Setting Up the Development Environment for SharePoint Server: http://msdn.microsoft.com/en-us/library/ee554869%28office.14%29.aspx
Extract the Language Pack with “SharePointLanguagePack.exe /extract:C:\ExtractedLanguagePack”
Modify the config.xml file in Files\Setup folder
Add “<Setting Id="AllowWindowsClientInstall" Value="True"/>”
Install the Language Pack
SharePoint Foundation
SharePoint Server
Run Configuration Wizard